/* ifdef.c -- 使用条件编译*/
#include <stdio.h>
#define JUST_CHECKING
#define LIMIT 4

int main() {
    int i;
    int total = 0;

    for(i = 1; i<=LIMIT;i++){
        total += 2 * i * i +1;
#ifdef JUST_CHECKING
        printf("i = %d, running total = %d\n",i,total);
#endif
    }
    printf("Grand total = %d\n",total);

    return 0;
}
